Show new flutter tool and its use in the widgets dir.

examples/README.md

@@ -2,15 +2,22 @@ Flutter Examples
 ================
 
 This directory contains several examples of using Flutter.  Each of these is an
-individual Dart application package.  If you wish to run them with `sky_tool`
-then you will want to run `pub get` inside their directory before running
-`./packages/sky/sky_tool start`.
+individual Dart application package.
 
-1. *Hello, world.* The [hello world app](hello_world) is a basic app that shows
+To run a sample with the `flutter` tool, run `pub get` inside its directory,
+then run `flutter start`. (See the
+[getting started guide](https://flutter.github.io/getting-started/) to install
+the `flutter` tool.)
+
+Available examples include:
+
+- *Hello, world.* The [hello world app](hello_world) is a basic app that shows
    the text "hello, world."
 
-2. *Stocks.* The [stocks app](stocks) is an example of a typical mobile app
+- *Stocks.* The [stocks app](stocks) is an example of a typical mobile app
    built using Flutter. The app shows a list of all the stocks in the NASDAQ.
 
-3. *Widgets.* The [widgets app](widgets) contains a number of Flutter widgets so
-   you can experiment with them in a simple container.
+- *Widgets.* The [widget apps](widgets) demonstrate a number of Flutter widgets
+   so you can experiment with them in a simple container. There is no main.dart
+   in this directory because each file is a standalone sample. To run a
+   particular file, use `flutter start -t filename.dart`.